As modern electronics evolve, they continue to shrink in size, yet increase in power density, and in the amount of heat they generate during operation. In order for these electronic devices to perform properly, their temperature must be strictly controlled within a given temperature range. Often, designers will attach heat sinks to the electronic devices to dissipate this excess heat. Typically heat sinks include fins or pins to increase the surface area of the heat sink within a constrained space and thus correspondingly increase the heat transfer capacity of the heat sink.
Many electronic systems include more than one heat generating device. Often it is desirable to attach heat sinks to multiple heat generating devices on one or more printed circuit boards. However, difficulties arise when a single heat sink is attached to multiple heat generating devices on a common printed circuit board or on multiple printed circuit boards. Many times the heat generating devices are of different thicknesses, or the top surfaces of the heat generating devices are in different planes and may not even be parallel, requiring corresponding topography on the base of the heat sink to allow high quality thermal coupling between the heat sink and the multiple devices. This greatly adds to the expense of the heat sink, and in some cases, may not even be possible if the stack up tolerances of the multiple devices are large enough that the variations in stack up tolerances are too large for whatever gasket (or other heat coupling technology) is used to thermally couple the heat generating devices to a single heat sink, whereas it is relatively easy to thermally couple a single heat generating device to a heat sink.